1. Technical Field
This invention is related to storage systems, and more particularly to an apparatus for movably supporting a storage system for rolling movement along a plurality of flat tracks secured to a floor without the use of a carriage for supporting the storage units of the system.
2. Background
Moveable file storage apparatuses are used in a wide variety of applications to increase storage density, and particularly in applications where a large amount of inventory or various items are stacked on large shelving units that need to be accessed periodically. Such systems typically include a number of moveable storage units positioned adjacent one another on a plurality of tracks or guide rails to form an elongated row. Each row of storage units are interconnected such that an entire row can be moved easily along the tracks or guide rails to allow access to adjacently positioned rows of storage units. Thus, by movably supporting various rows of storage units, the floor space required for any given number of rows of storage units is reduced dramatically. This significantly reduces the cost of storing inventory and other articles such as files, books, etc. by allowing a significantly larger number of such articles to be stored in any given space. These forms of moveable storage systems find particular utility in warehouses and other like buildings, but are just as easily adaptable to office settings to store books, files, X-rays and other forms of records which need to be accessed periodically by office personnel.
Such storage systems as described above typically employ a "carriage" which is a rigid, rectangular, frame-like device comprised of a plurality of interconnected members which runs the full length of a row of storage units supported thereon. The carriage includes typically several pairs of spaced apart wheels or rollers. The wheels or rollers enable the entire carriage to be moved along two or more parallel placed guide tracks, which are often V-groove type tracks. Each row of movable storage units thus requires its own carriage so that each row can be moved independently of the other rows. Thus, a storage system incorporating two movable rows of storage units will need two carriages, a system with three movable rows of storage units will require three carriages, and so forth.
The carriage has heretofore been necessary for providing easy rolling movement of medium to long rows of movable storage units because of the insufficient structural integrity of most side-by-side storage units configured in a long row. Simply supporting the storage row at various points by a plurality of pairs of wheels or rollers has not traditionally been thought to be a workable option because the various sections making up a medium to long length row of storage units, without being supported by a highly structurally rigid carriage, would tend to move not perfectly simultaneously together, but rather one or more sections would slightly lead or lag relative to the other sections. Usually, the portion of the storage row which is driven by a gear or sprocket will tend to "lead" the other portions of the storage row. This causes the wheels to want to roll along paths not straight and parallel to one another. In the art this is termed "racking".
With systems employing V-groove tracks mounted to the floor, the wheels which are not moving in straight paths will tend to bind as they try to move in a slight arc and will tend to want to climb out of the V-groove of the track. With systems employing a flat track and wheels having a flat (i.e., non-radiused) rolling surface, a "scrubbing" action of the wheels along the track surfaces will occur when all of the wheels are not rolling in perfectly parallel paths. This scrubbing action will impede smooth rolling movement and require an individual to use additional force to move the entire storage row. It will also significantly increase the wear and tear of the wheels and the track. Thus, the use of a highly rigid carriage incorporating several pairs of spaced apart parallel wheels has been necessary to ensure that all of the wheels roll along paths that are as straight as possible, and that the wheels run along perfectly parallel paths. The need to install the tracks precisely parallel is equally important in obtaining satisfactory operation of such conventional systems.
Even when using a highly structurally rigid carriage, however, the problem of an unlevel floor can still produce the above-described problems. Shimming the tracks on which the wheels of the carriage roll can often help to reduce the effects of the unlevel floor, but it is often difficult, or impossible, to completely correct the unlevelness of the tracks. Floor unlevelness can also significantly increase the force needed to roll the storage row along its tracks.
Further to the above, the carriage represents a significant cost of a movable storage system. Due to its size and weight, the carriage also adds significantly to the cost of shipping the storage system. Since assembly of the carriage(s) is/are required at the site where the movable storage system is to be installed, the time, and thus the cost, of installation is increased. The use of the carriages also complicates the installation and requires a more highly skilled installation worker to assemble and install the movable storage system, as well as to carefully and precisely install the tracks. The tracks need to be carefully installed precisely parallel to one another and shimmed, if necessary, to ensure that the tracks are as level as possible relative to each other, and that each track is also level end-to-end. Thus, it would be highly desirable to provide a movable storage system which provides for a very smooth, low effort rolling action without the need for a conventional carriage.
It would also be highly desirable to provide a movable storage system where the storage units are supported at a plurality of points by rollers or wheels which ride on flat tracks, and where the rollers or wheels are not subject to the scrubbing action described above if the rollers move along a slight arc rather than a perfectly straight (i.e., linear) path.
It would also be highly desirable to provide a movable storage system which does not require a carriage for supporting the various storage sections, and which further incorporates a plurality of support wheels which are able to "float" on corresponding flat tracks such that the scrubbing action described above is essentially eliminated when the support wheels are not moving in perfectly straight, parallel paths.
It would also be highly desirable to provide a movable storage system which can be driven at one longitudinal end thereof by a gear or sprocket, which does not require a carriage, and which incorporates a plurality of radiused support wheels which are allowed to "float" over corresponding flat tracks to thereby essentially eliminate the scrubbing action suffered by prior art movable storage systems.